Field of the Invention
The disclosure relates to image sensors, and more particularly to image sensors having isolated partitions in a filter array.
Description of the Related Art
Recently, image sensors have been widely used in various image-capturing apparatuses, for example video cameras, digital cameras and the like. Image sensors, such as charge-coupled device (CCD) image sensors or complementary metal-oxide semiconductor (CMOS) image sensors, have photoelectric converters for converting incident light into electric signals. The image sensors have a pixel array and each pixel has one photoelectric converter. The image sensors also have logic circuits for transmitting and processing the electric signals.
Moreover, image sensors usually have a color filter layer for generating color images. The color filter layer may contain a primary-color filter of red (R), blue (B) and green (G) segments stacked over the light-receiving surface of two-dimensionally arranged photoelectric converters. The color filter layer has a predetermined pattern such that each of the color segments corresponds to one photoelectric converter.
In some examples, the red (R), blue (B) and green (G) segments are connected together to form a connected color filter layer. The pixels of the image sensors corresponding to the red (R), blue (B) and green (G) segments of the connected color filter layer, respectively, have different quantum efficiencies (QE). In some other examples, a grid structure is disposed between the red (R), blue (B) and green (G) segments to form a discontinuous color filter layer. The pixels of the image sensors corresponding to the red (R), blue (B) and green (G) segments of the discontinuous color filter layer, respectively, also have different quantum efficiencies (QE).
The quality of the image sensors is indicated by many characteristics, such as dynamic range, sensitivity, responsiveness, uniformity, etc. When an image of an object is captured under a transfer between high and low illumination intensities using the image sensor, the dynamic range is particularly important. There is a need to enhance the quantum efficiency (QE) of the pixels of the image sensors for high dynamic range application.